“You simply upload your application, and Elastic Beanstalk automatically handles the deployment details of capacity provisioning, load balancing, auto-scaling, and application health monitoring. At the same time, with Elastic Beanstalk, you retain full control over the AWS resources powering your application and can access the underlying resources at any time.”

You will have to pay for using a server and storage on the Amazon cloud, although it sounds like there are no other costs.

“There is no additional charge for Elastic Beanstalk – you only pay for the underlying AWS resources (e.g. Amazon EC2, Amazon S3) that your application consumes.”